Simplify NLLB: remove 503 handling, clean cache logic, remove unused None path

src/streamlit_app.py

@@ -571,7 +571,7 @@ def _get_nllb_api_url():
     return url if url.startswith("http") else "https://" + url
 
 def translate_with_nllb(text, target_language, _api_url):
-    """Translate via NLLB API. Uses session-state cache so switching back is instant."""
+    """Translate via NLLB API. Session-state cache so switching back to a language is instant."""
     cache = st.session_state.setdefault('_nllb_cache', {})
     key = (text, target_language)
     if key in cache:
@@ -587,12 +587,9 @@ def translate_with_nllb(text, target_language, _api_url):
         )
         if response.status_code == 200:
             result = response.json().get(api_lang, '❌ Translation not found in response')
-            cache[key] = result  # only cache successful results
+            cache[key] = result
             return result
-        elif response.status_code == 503:
-            return None  # GPU busy — caller keeps previous result, not cached
-        else:
-            return f"❌ API Error: {response.status_code}"
+        return f"❌ API Error: {response.status_code}"
     except Exception as e:
         return f"❌ Error: {str(e)}"
 
@@ -813,11 +810,10 @@ def main():
                     result = translate_with_nllb(input_text, target_lang, _get_nllb_api_url())
                 else:
                     result = ""
-                if result is not None:  # None = server busy (503), keep previous result
-                    st.session_state.translation_result = result
-                    st.session_state.last_translated_text = input_text
-                    st.session_state.last_translated_model = selected_model_option
-                    st.session_state.last_translated_lang = st.session_state.target_language
+                st.session_state.translation_result = result
+                st.session_state.last_translated_text = input_text
+                st.session_state.last_translated_model = selected_model_option
+                st.session_state.last_translated_lang = st.session_state.target_language
 
             output_area.text_area(
                 f"Translation ({st.session_state.target_language})",